Hmm, first and foremost, I am suggesting developers to take advantage of Java 5.0 APIs in their own applications.

Now, if the application server itself has concurrency issues, I understand that the average application developer would not know how to fix it. But you can at least find the contention point in the source code (in the case of an open source app server) and raise a issue (bug report or feature request) to the open source developers in that community ...